Recognition of Chirality

A chiral terephthalic acid derivative, 2,5-bis[10-(2-methylbutoxy)decyloxy]ter-ephthalic acid (Fig. 15), with two identical stereogenic centers, has been investigated by De Fey ter et al. [18]. 

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An understanding of the recognition of chirality at a molecular level has become of interest in many fields of chemistry and biology. In the past decade, many attempts to clarify the mechanism of chiral recognition on CSPs for liquid chromatography have been made by means of chromatography, NMR spectroscopy,199 202 X-ray analysis, and computational methods.203 - 206 The successful studies have been mostly carried out for the small-molecule CSPs, especially cyclodextrin-based CSPs and Pirkle-type (brush-type) CSPs. In contrast, only a few mechanistic studies on chiral discrimination at the molecular... 

There are several cases that have addressed molecular recognition of chiral drugs by modified CDs127 as well as inclusion complexes of cationic, anionic and neutral organic compounds128 in order to understand the role of hydrophobic and electrostatic interactions between the functional groups on host and guest. 

The four different groups attached to a chiral carbon can be different elements, isotopes, or functional groups, and chiral centers can be present in bodi open-chain molecules or cyclic compounds. The recognition of chirality and chiral centers in molecules is an important step in determining the numbers of stereoisomers that are possible for a given compound. 

The prototype of a first fluorescence sensor for enantioselective recognition of chiral amino alcohols was synthesised by Pu et al. by linking phenylacetylene dendrons to an axially chiral binaphthol core unit (see Fig. 4.71) [14c, d, 25],... 

Work by Irie et al. on the control of intermolecular chiral l,l -binapthyl fluorescence quenching by chiral amines [66] and the use of 1,1 -binaphthyl in the recognition of chiral amines by Cram [67] were the inspiration behind the design of 26 (R or S). Chiral recognition of saccharides by 26 (R or S)... 

RECOGNITION OF CHIRALITY REMOTE FROM REACTION CENTER... 

Figure 4. Recognition of chiralities at various distances from reaction centers...

The bicyclic receptors 40 and 41 were also prepared for enantioselective recognition of chiral carboxylates [69, 70]. The substitution of two benzene rings by pyridines in the receptor 41 enriched this molecule with two additional sites capable of hydrogen bond formation. 

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